Loud-speaker armature



Aug. 5, 1930. N. BALDWIN LOUD SPEAKER ARMATURE Filed July 5, 1927 INVVENTQR Patented Aug. 5, 1930 PATENT OFFICE NATHANIEL BALDWIN, OF EAST MILL GREEK, UTAH LOUD-SPEAKER ARMATURE Application filed July 5, 1927.

The present invention appertains to loud speakers, and is particularly an improvement on my telephone receiver, patented May 10, 1910, No. 957,403.

The object is to obtain greater efiiciency and more accurate reproduction by providing a stiffer armature without increasing its weightor changing its dimensions.

I attain this object by the mechanism illustratd in the accompanying drawing in which Fig. 1 is a side elevation of a part of the loud speaker containing the improved armature, Fig. 2 is a cross section of the same part along the line A B of Fig. 1 with the addition of polepieces to the parts shown in Fig. 1. Fig. 3 is a top View of the armature only, and Fig. 4 is a section of the armature along the line C D of Fig. 3.

In the several figures of the drawing the armature 1 is shown with fulcrum wires 2 attached by which it is supported within the spool. 3. The U-sha-ped polepieces 4 and 5 inclose the spool 3 and the limbs of said polepie-ces act upon the ends of said armature. A connecting rod 6 communicates the movement of the armature to a diaphragm or other acoustic element.

The armature as commonly used in such devices is made of thin sheet iron or sheet steel and is more or less flexible. The move ment of the end of the armature to which the connecting rod 6 is attached is transmitted without much loss to the acoustic element, but a considerable part of the movement of the otl er end of said armature is lost by the flexibility of the armature. In the present structure I stiffen the armature and avoid much of this loss by forming a depression 7 in the armature, or otherwise beading it. Practical use of this improved armature has proved that it increases the efficiency of the instruments in which it is used, and also im proves the quality of reproduction.

I claim:

1. In an electromagnetic vibratory device,

Serial No. 203,544.

NATHANIEL BALDWIN. 

